The present disclosure relates to a power amplifier circuit. As a power amplifier circuit used in a mobile communication device, such as a cellular phone, “Evolution of Power Amplifier for mobile applications” Satoshi Tanaka, International Meeting for Future of Electron Devices, Kansai (IMFEDK), 2013 IEEE, pp 112-113 discloses a power amplifier circuit using a heterojunction bipolar transistor (HBT). Japanese Unexamined Patent Application Publication No. 2015-115835 discloses a power amplifier circuit including two cascode-connected HBTs.